(1) Field of the Invention
The invention relates to hand tools for installing flexible tubing in tight fit within openings in the wall of a larger rigid tube.
(2) Description of the Prior Art
In the prior art, such operations as the invention provides have been accomplished by unaided manual methods. Recently, there has been increased interest in solar energy for water and space heating and consequently there has been considerable engineering effort toward development of economical and efficient solar collectors, most of which rely on the heating of a fluid such as water. For air space heating, a subsequent heat exchanger is employed.
One particularly desirable solar collector structure of low cost and easy installation includes a number of flexible tubes (of a suitable soft plastic material) which may be loosely placed along a roof or other flat surface exposed to the sun. These tubes are connected in parallel between input and output headers which are larger diameter rigid plastic tubes or pipes, for example of PVC or ABS plastic types. As a result, a large effective solar collection area can be achieved economically.
One of the significant manufacturing (or field assembly) steps concerns the insertion of the flexible tubes into holes in the larger, rigid header pipes. Since there are a large number of these connections in such a solar collector structure, it is important that the cost of each connection be minimized. Obviously, any number of connectors are available which would meet the requirements. However, these add considerable cost, even if they are individually relatively inexpensive. Moreover, hand installation is still necessary.
One inexpensive connection structure makes use of an inner liner inserted into the soft, flexible tubing. When the lined end of the flexible tubing is inserted into an opening with an interference fit, the soft material of the flexible plastic tubing is circumferentially gripped between the opening and the liner due to the resulting material compression.
The assembly of the solar collector of the type described is basically a field operation, each installation being more or less customized to the available mounting surface. In the past, the assembly operation has been an unaided hand operation, the liners being hand inserted and the flexible tubing being manually pushed and twisted to force it into place in its corresponding opening in the header pipe. There has clearly been a need for a tool capable of speeding this operation and reducing the manual effort required.
The manner in which the invention responds to the aforementioned need will be understood as this description proceeds.